You don't have to do any of that. Its their job to report income and pay taxes. Withholdings are a "convenience" not a requirement. Furthermore you weren't their employer, they provided a service to you.
[1] https://www.irs.gov/publications/p926#en_US_2024_publink1000...
It's likely 90% of the population don't follow this tax law.
I eventually got everything sorted with the help of an accountant and they confirmed this.